Air conditioning system



March 18, 1969 A. B. NEWTON AIR CONDITIONING SYSTEM Filed Oct. 11, 1967C re d w a a 0 v WW E E N w m z W?!) g l/.N\ D m M w w. 2 w w E w A].

D.C. POWER SUPPLY TO RETURN AIR SYSTEM, OR OUTDOORS ZONE 5 INVENTORALW/Nfi NEW7'0/V BYWJM ATTORN EV United States Patent 3,433,025 AIRCONDITIONING SYSTEM Alwin B. Newton, York, Pa., assignor to Borg-WarnerCorporation, Chicago, Ill., a corporation of Illinois Filed Oct. 11,1967, Ser. No. 674,499 US. Cl. 62-3 Int. Cl. F25b 21/00 7 ClaimsABSTRACT OF THE DISCLOSURE Background of the invention;

This invention relates to air conditioning systems. More particularly,it relates to air conditioning systems wherein thermoelectric elementsare employed to effect desired temperature and humidity control ofconditioned air sup plied from a central source to separate areas orzones with unequal loads.

In many situations, air conditioning systems used to control thetemperature and humidity in a given area experience unequal loadsbetween zones of the area to be served. For example, during the winter,the area about the perimeter of a building may be relatively cool incomparison to its core, while the situation may be the opposite duringthe summer. Furthermore, the temperature and humidity load in an area ofthe perimeter or the core may vary considerably in a given time period.The load requirement will depend upon the intensity of sunlightimpinging on the walls and windows of the building, the heat dissipatedin the area from ofiice equipment and similar apparatus and othervariable factors.

Systems for controlling the temperature and humidity in situations suchas those described above have been proposed and used; however, each ofthem has been unsatisfactory, for reasons of extreme complexity orexcessive cost or lack of effectiveness.

Accordingly, it is a principal object of the present invention toprovide an improved air conditioning system which is effective tocompensate for variable zone loads.

Summary of the invention Very generally, the present invention includesa thermoelectric element or apparatus mounted in a supply duct in amanner such that the conditioned air supplied by a central airconditioner source is divided into separated streams which areselectively acted upon and coupled to line ducts extending into the areaor zones of varying load. Utilizing the thermoelectric device, heat canbe pumped from the stream flowing from the supply duct to one line ductto the stream flowing from the supply duct to another line duct.Alternatively, the operation can be reversed to supply colder air to thearea or zone supplied through the other line duct by reversing thecurrent flow to the device. Selective heating or cooling also can beprovided by employing bypass dampers which determine whether theconditioned air is returned to the air system of the air conditionersupplying the system, rejected outdoors, or otherwise utilized.

The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts which will beexemplified in the construction ice hereinafter set forth, and the scopeof the invention will be indicated in the claims.

Description of the drawings For a fuller understanding of the nature ofthe invention, reference should be had to the following detaileddescription taken in connection with the accompanying drawing in which:

FIGURE 1 is a schematic block diagram generally illustrating an airconditioner system having a thermoelectric element installed therein, inaccordance with the present invention;

FIGURE 2 is a perspective view, partially broken away, of thethermoelectric element of the system of FIGURE 1;

FIGURE 3 is a detailed perspective view of one of the strings of thethermoelectric elements and heat exchange fins used in the unit ofFIGURE 2; and

FIGURE 4 is a partial block diagram, generally illustrating the mannerin which the conditioned air in a line duct can be directed forsubsequent utilization or rejection outdoors.

Detailed description Referring now to the drawing, in FIGURE 1, there isillustrated, in block diagram, an air conditioning system 10 exemplaryof the invention including a supply duct 12 which is coupled to acentral air conditioning unit or source 14, and which suppliesconditioned air to a thermoelectric element or apparatus 16 which in theillustrated embodiment is of the cross-flow type. That is, the apparatus16 is of the type which includes separated flow paths comprised ofalternating sections which direct one stream of air at right angles withrespect to another stream. In this respect, the apparatus 16 preferablyis a thermoelectric apparatus of the type disclosed in copending UnitedStates patent application, Ser. No. 625,392, filed Mar. 23, 1967, byAlwin B. Newton. It should be understood, however, that a counter flowor parallel flow heat exchange system would also be operable.

More specifically, as fully explained in the abovementioned copendingapplication, the apparatus 16, as can be best seen in FIGURES 2 and 3includes alternate groups of sections 18 and 20 defining flow passagesfor streams of air passing at approximately right angles to each other.

A plurality of heat exchange fins 22, 24 extend across the flow paths 18and 20, respectively. These fins 22, 24 are in thermal and electricalcontact with alternating N and P-type thermoelements 26, 28,respectively, extending between adjacent fin sections. Thethermoelements entered between adjacent sections and are arranged suchthat current flow in one direction will provide for pumping of heat fromthe sections 18 to the sections 20 and reverse current flow will providefor pumping of heat in the opposite direction.

As fully described in copending application Ser. No. 625,392, the fins22, 24 act as both heat transfer elements and as electrical conductorsto conduct the unidirectional electrical energy in series through thethermoelements. Bus bars 30 at opposite ends of the unit conduct currentfrom one string of thermoelements and fins to an adjacent string. Theunidirectional electrical energy, supplied by some suitable source suchas the DC power supply 32, is connected to a first terminal 34 and flowsthrough the string at the lower right-hand section of the unit, asillustrated in FIGURE 2, to the opposite end. Each of the strings iselectrically insulated from an adjacent string by epoxy resin or othersuitable insulating material 36. The current emerges from the oppositeend of the string to be transferred by a bus bar (not shown) to thesuperjacent string. Flowing from right to left in the latter string, itreaches the left-hand end of the module and passes through bus bar 30ato another superjacent string and so forth through the entire unit untilit emerges at terminal 38 connected to the other side of the D-C powersupply 3 2. Current passing into the plane of the bus bars, as shown inFIGURE 2, is denoted by and current passing out of the plane is denotedby 0.

As can be best seen in FIGURE 3, each of the thermoelements 26, 28 issoldered, or otherwise mechanically and electrically secured, between apair of generally rectangular conductor plates 42 of copper, aluminum orother suitable material. The other side of plates 42 are soldered orotherwise secured to the fins 22 and 24. The space surrounding thethermoelements may be filled with insulating material 44, such aspolyurethane foam, or other suitable material having low thermalconductivity and good moisture resistance.

The thermoelectric conditioning apparatus 16 is positioned with respectto the supply duct 12 so that the conditioned air from the central airconditioned source 14- can simultaneously flow through sections 18 and20 in one direction (indicated by the arrow 46 and hereinafter referredto as circuit 46) to a line duct 48 and in another direction (indicatedby the arrow 50 which is hereinafter referred to as circuit 50) at aright angle to the first, to a line duct 52. The line duct 48 couplesthe conditioned air from the apparatus 16 to a zone A which may be, forexample, an area or room on the perimeter of a building. The

. line duct 52 likewise couples the conditioned air from the apparatus16 to a zone B which may be, for example, in the core of the building.

In operation, conditioned air is supplied from the conditioned airsource 14 through the supply duct .12 to the apparatus 16 at atemperature suitable for most of the zones served usually at 55 to 65 F.Power is supplied to the apparatus 16- by the D-C power supply 32. Aswitch 54 for reversing the polarity of the power supplied theretoadvantageously is provided, for controlling the operation of theapparatus 16 in the well-known manner and as described more fully below.Any suitable means (not shown) also can be provided for controlling thelevel of D-C voltage applied to the apparatus 16.

If local cooling or dehumidification is needed, the apparatus 16 isoperatively energized. The thermoelements effect pumping of heat fromthe stream of conditioned air passing through the sections 18 to thestream of conditioned air passing through the sections 20. The cooledand dehumidified air passing through sections 18 then flows through lineduct 48 to zone A. The heated stream of air passes along circuit 50through duct 52. By choosing the air quantity through circuit 46 so thatthe temperature of the conditioned air supplied to line duct 52 is equalto the temperature in zone B, the sensible heat load of zone B is noteffected. Conversely, the conditioned air supplied to zone A throughcircuit 46 of the apparatus 16 and the line duct 48 effectively reducesthe sensible heat load of that zone. Reducing the quantity of airthrough circuit 50 adds to the room sensible load in zone B, so thatcontrol of the room sensible load is possible.

If added cooling and dehumidification is needed in zone A supplied byline duct 48, the conditioned air supplied to line duct 52 is directedby means of bypass dampers, for example, bypass dampers 56, asillustrated in FIG URE 4, to the return air system of the airconditioner source 14, or it may be rejected to atmosphere.

Where adjacent zones have oppositely varying heat sensible loads, theconditioned air through circuit 46 to line duct 48 is supplied, cooledand may be dehumidified, as described above, While the heatedconditioned air through circuit 50 to line duct 52 is supplied to a zoneneeding less cooling. In an opposite season, the heat sensible loadconditions in each of these zones may reversibly change. In such cases,the switch 54 is reversed to operatively energize the apparatus so thatthe conditioned air in line duct 52 is cool and the conditioned air inline duct 48 is heated.

A thermostat 60 advantageously can be provided in one of the zones, suchas the zone A, as illustrated, for controlling the D-C power supply 32to energize the apparatus '16, in accordance with the requirement forconditioned air in that zone. The thermostat 60 likewise can be adaptedto control the operation of the switch 54, to automatically switch it toreverse the operative condition of the apparatus 16, if desired.

A complete air conditioning system may include a number of systems likethe system 10 placed in various predetermined strategic positions withina building. A modulated central air conditioner source such as thesource 14 can thereby be easily adapted to handle the building's averagesensible heat load. A number of thermoelectric elements or apparatuslike the apparatus 16 are installed at convenient locations to providethe needed trimming of the conditioned air supplied to these locations,as required.

It can be seen from the above description that the thermoelectricapparatus 16 can be easily installed inconventional air supply ducts. Itis only necessary to provide that the conditioned air from the airconditioning source 14 flow through both the circuits 46 and 50simultaneously and that line ducts are provided to convey theconditioned air from the apparatus 16 to the various zones or areas tobe air conditioned. Appropriate voltage regulating means are provided tocontrol the degree of energi- Zation of the thermoelectric apparatus 16to provide conditioned air at the desired temperature and humidity. Inaddition, switch means are provided to reverse the operative state ofthe thermoelectric apparatus 16. Thermostats and humidistats can beprovided to automatically control the supply of power to the apparatus16, as desired. Additional trimming of the conditioned air supplied to aparticular zone or area can be provided by means of individual unitslike the apparatus 16, installed and operated in the conventionalmanner.

Various features of the invention have been particularly shown anddescribed in connection with the illustrated embodiments of theinvention. However, it must be understood that these particulararrangements are for illustrative purposes and that the invention is tobe given its fullest interpretation within the terms of the appendedclaims.

What is claimed is:

1. An air conditioning system including: a source of conditioned air; aconditioned air supply duct connected to said source; a thermoelectricapparatus disposed within said supply duct to receive said conditionedair, said apparatus being divided into sections defining at least twoseparated flow paths for said conditioned air, and including a pluralityof thermoelements disposed between said separated flow paths to pumpheat from the conditioned air in one of said flow paths to theconditioned air in the other upon energization of said elements; asource of power connected to said thermoelectric apparatus forenergizing said thermoelements, and at least one line duct connected toone of said flow paths to receive conditioned air therefrom, said lineduct being connected to a zone to be conditioned.

2. An air conditioning system as claimed in claim 1, wherein saidthermoelectric apparatus is of the crossfiow type.

3. An air conditioning system as claimed in clam 1, wherein a pair ofline ducts are provided each one of which is connected to one of saidseparated flow paths to receive conditioned a-ir therefrom, said lineducts being connected to separate zones of an area to be conditioned.

4. An air conditioning system as claimed in claim 3, wherein said systemfurther includes bypass damping means in at least one of said lineducts, and a venting line duct coupled to said line duct, whereby theair flowing through said line duct can be coupled back to said airconditioning source or rejected to atmosphere.

5. The air conditioning system of claim 3, further including switchmeans for reversing the polarity of the source of power coupled to saidthermoelectric apparatus.

6. The air conditioning system of claim 3, further including temperaturesensitive control means in the zone supplied conditioned air by at leastone of said line ducts for controlling the operation of said source ofpower to selectively energize said thermoelements,

7. The air conditioning system of claim 3, further including athermoelectric apparatus positiona-bly mounted in at least one of saidline ducts for trimming the conditioned air supplied to the area or zoneserviced by said one line duct.

References Cited UNITED STATES PATENTS WILLIAM J. WYER, PrimaryExaminer.

U.S. Cl. X.R.

